@DawnscrollWell, Arcon didn't have Teknall's support and supposedly it will be more tech advanced than Galbar. Saying there is no tech without him is an exaggeration.
On the same way, I think that outside of the Realta, the threats you listed are somewhat minor. Hordes would be slowly eaten away by attrition as Vestec's support of it disappeared. Jvan's sculptors would just go back to wandering alone, as they always did.
I mean, it would be pretty comfy for me as a player if Ilunabar being hurt meant all beauty in the world would die away, all cultures would go poof and all that. But I don't think that is how the game was set and the way the death of gods has so far been handled confirms that.
So far the only case of a god being in a bad spot having a bad effect on the world has been Slough. But sincerely, the Aimless Time was interesting as a one-time thing, a repeat would be too much.
Not that I think any active god should die either way. Unless the player decides to kill them off.
Lord Zee
Ashh
Frettzo
Vec